Beacon lights are known and one of the typical requirements is to transmit a bundle of light over a relatively wide angle, typically 360 degrees, in a horizontal plane over a relatively small vertical angle, i.e. with a limited beam spread, to provide an obstruction warning in all directions. The definition of beam spread depends on the regulations to be applied. A common rule is to consider the beam spread at full width half maximum (FWHM). The beam spread is then considered to be the angle of the full width of the beam at half the maximum of the peak intensity. Typically the beam spread is the angle of the beam measured in a vertical plane over which the intensity of the emitted light is greater than e.g. 50%—depending on the regulations this may be 10%—of the peak intensity of the emitted light. The beam spread may typically be on the order of several degrees, e.g. 5 degrees or 2.5 degrees. For certain applications such as offshore obstruction lights or aviation obstruction lights, the desired pattern of emitted light is defined by rules and/or regulations.
A typical beacon light comprises a plurality of beacon light optics arranged in juxtaposition such that the optical axes of the beacon light optics are angled relative to each other and the exit areas of the beacon light optics face outwards. The beacon light optic usually is of a rotation symmetrical type, e.g. a paraboloid and may be a massive optic or an air-filled optic. A massive optic can be a massive plastic optic or a massive glass optic. Each optic typically comprises a single light emitting element, preferably an LED-element.
A drawback of the known beacon light is that a lot of optics are needed to form a beacon light with a 360 degrees angular distribution. Since an individual beacon light optic is relatively expensive, and relatively heavy, the beacon light may become relatively large, expensive and/or difficult to install.
Therefore, there is a need for a beacon light that can be more cost effective and/or more compact.
Furthermore, each light emitting element consumes energy, and, in particular for systems operating on batteries in case of emergency, energy consumption of the beacon light is preferably as low as possible, because less energy consumption also means a smaller battery pack. Since the batteries used for these emergency purposes are relatively expensive, there is a wish to minimize the battery pack required.
Thereto, an embodiment provides a beacon light optic according to claim 1.